As the electronics industry advances, and production of light weight components increases, the development of new materials gives producers increased options for further improving the performance and ease of manufacture of such components. Adhesive compositions are used for a variety of purposes in the fabrication and assembly of semiconductor packages and microelectronic devices. The more prominent uses include bonding of electronic elements such as integrated circuit chips to lead frames or other substrates, and bonding of circuit packages or assemblies to printed wire boards.
Adhesives used in the electronic packaging industry typically contain a thermosetting resin, combined with a filler and some type of curing initiator. These resins are primarily used in the electronics industry for the preparation of non-hermetic electronic packages. Adhesives useful for electronic packaging applications typically exhibit properties such as good mechanical strength, curing properties that do not affect the component or the carrier, and Theological properties compatible with application to microelectronic and semiconductor components. Examples of such packages are ball grid array (BGA) assemblies, super ball grid arrays, IC memory cards, chip carriers, hybrid circuits, chip-on-board, multi-chip modules, pin grid arrays, and the like.
In addition, there are many potential applications for adhesives having electrically insulating properties. Such materials must, however, satisfy a combination of criteria, i.e., in addition to exhibiting a low dielectric constant, such materials must also have good dispensability and good adhesion properties. Non-conductive fillers traditionally employed for the preparation of adhesives having electrically insulating properties include aluminum nitride, boron nitride, alumina, silicon dioxide, and the like.
The rheology of an adhesive paste is a very important consideration for manufacturing purposes. For example, separation of the filler from the resin in the syringe, a clean break of adhesive between each dispense thereof, and the presence of drip-free syringes in the dispense operation are all important attributes for consistent dispensing properties.
For all these applications, the microelectronics industry continues to require new adhesive formulations that are able to meet its varying demands. Accordingly, there is a need for the development of compositions and formulations to address the requirements of this rapidly evolving industry.